Such back rest structures for vehicle seats are commonly provided with a back panel element and a seat back frame element which are made of metal. From U.S. patent publication U.S. 2006/175887 A1, a rear seat backrest frame for a rear backrest component of a vehicle seat is known, having at least one main plate, a left and right vertically extending lateral hat-shaped section, one upper and one lower transversely extending hat-shaped section, the hat-shaped sections are welded to the front surface of the main plate. Such metal structures have the drawback that their weight is considerable and that the production process involves methods, such as welding, that are costly and tend to conduct to comparably high tolerance ranges of the finished product.